very confusing test results - oral challenge? - Peanut Allergy Information

very confusing test results - oral challenge?

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Hi experts! Just found this board while trying to find some info to clarify DS's lastest test results. Would anyone care to share an opinion?

Last years's RAST test was extremely low level 1. Follow-up skin test was positive with an immediate hive.

This week's skin test was negative, so allergist scheduled a RAST and a follow-up appointment for an oral challenge. I just got back the RAST results which were still a very low level 1, but slightly higher than last year. I don't have the exact number, but the nurse called it a very low level 1.

They still want us to do the oral challenge on Thursday. I was reading some of the posts on here, and now I am a bit hesitant to do it. The test results are so confusing! It was the skin test last year that freaked me out since it was an instant reaction. This year - nothing. But now the RAST is a bit higher? I swear, the PA will drive a person mad trying to make sense of it!

Thanks in advance for any advice/opinions!


On Aug 14, 2007

Hi Lynne! I find your post interesting. Could you go and read mine? ("immunoCap results are in!") I'm with you with the confusion. My DD has the opposite problem. Neg for PA in bloodwork but 3+ on SPT. very large wheal. It's so confusing. I think my daughter will need another SPT.

It is so confusing. I'm sorry I can't help you. Only wish you the best, and good luck on Thursday if you go through with the food challege.

By the way, may I ask what kind, if any, of reaction has your son had?

------------------ Kara mom to 4, wife to 1 Elise 5- (eczema, NKA) Mary 3- (egg, peanut, beef, pork, chicken, turkey, organge, avoiding: tree nuts, shellfish, most dairy, eczema) Franklin 2- (eczema, NKA) Cecelia 7mos-(NKA)

On Aug 14, 2007

I'm pretty new to this... but I will tell you what my son's allergist said. He is in the moderate range at 0.82. The dr said we will do the RAST again in 2 years when he is 4. If it goes down we will discuss whether to do an oral challenge.

Before doing the challenge I would want to know why your allergist thinks it would be safe to do the challenge even though the RAST went up. That would be an exposure and if you had a false neg on the skin test you would/could make the allergy worse.

I understand that the skin test was negative... but well I'd just want to know more first.

Good Luck!

There are many on here that know much more than I... that's my thought on it though.

By pnkid06 on Aug 21, 2011

I have read an article about a study done that said a challenge done on an individual with a negative skin and a rast test under 15 is 90 something percent to pass the challenge. Many studies are similar, If you read into the studies you will get a better view of the statistics. Usually they look for a rast that consistently goes down, and they do several years of testing to verify this. Good Luck!